#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <math.h>
void set_strangle(int a, int b, int c)
{
    if (a == b && a == c)
    {
        printf("Equilateral triangle!\n");
    }
    else if ((a == b) || (a == c) || b == c)
    {
        printf("Isosceles triangle!\n");
    }
    else
    {
        printf("Ordinary triangle!\n");
    }
}
int main() {
    int a = 0, b = 0, c = 0;
    while (scanf("%d %d %d", a, b, c) != EOF)
    {
        if (((a + b) >= c) && ((a - b) <= c))
        {
            set_strangle(a, b, c);
        }
        else if (((a + c) >= b) && ((a - c) <= b))
        {
            set_strangle(a, b, c);
        }
        else if (((c + b) >= a) && (abs(c - b) <= a))
        {
            set_strangle(a, b, c);
        }
        else {
            printf("Not a triangle!\n");
        }
    }
    return 0;
}